This invention relates to rechargeable batteries, and more particularly to determining the capacity of a nickel cadmium (NiCd) battery. The battery capacity of NiCd batteries are determined by charging the battery to 100% state of charge and then discharging the battery at a constant current. The time required for the battery to discharge to a specified voltage is measured. The battery capacity in ampere-hour (A-hr.) is then calculated by multiplying the time in hours to discharge the battery by the constant discharge current. This method takes several hours of charging and discharging.
At the present time, there is no method for determining the capacity of a NiCd battery without discharging the battery.
There is, therefore, a need for a method to determine the capacity of a NiCd battery without discharging the battery.